#mongoose #unique validator #validator #unique mongoose

MongooseUniqueValidator.js

Schema.post('save', function (error, doc, next) {
  if (error.name === "MongoError" && error.code === 11000) {
    const result = {
      message: "ValidationError",
      errors: {},
    };

    Object.keys(this._doc).forEach(path => {
      const isDuplicate = error.errmsg.includes(`$${path}_1`);
      if (isDuplicate) {
        const value = this._doc[path];
        result.errors[path] = {
          message: 'is already used',
          kind: 'unique',
          path,
          value,
        }
      }
    });
    next(result);
  } else {
    next()
  }
});